STRUCTURAL ANALYSIS REPORT

OF
HIMALYAN GENERAL INSSURANCE BUILDING
KATHMANDU, NEPAL

Submitted By:
MRB & Associates
27/19 Seto Dhoka Marga (30475), Jamal, Kathmandu, Nepal
mrb.nassociates@gmail.com
December, 2018
 Table of Contents
1.0 INTRODUCTION .......................................................................................................... 2
2.0 STRUCTURAL SYSTEM FOR THE BUILDINGS .............................................. ...…4
3.0 GENERAL DATA FOR STRUCTURAL ANALYSIS ................................................. 5
4.0 LOAD CALCULATIONS .............................................................................................. 7
5.0 LOAD COMBINATIONS ............................................................................................ 12
6.0 ANALYSIS AND DESIGN PROCEDURE................................................................. 13
7.0 MODELING IN ETABS 2017 ..................................................................................... 14
8.0 DEFLECTION AND STOREY DRIFT ....................................................................... 19
9.0 MODAL PARTICIPATING MASS RATIOS ............................................................. 24
10.0 DESIGN OF STRUCTURAL ELEMENTS ................................................................. 25

Page | 1
1.0 INTRODUCTION

1.1 EXECUTIVE SUMMARY

This report has been prepared as a part of the structural engineering analysis and
design of Commercial Building to be built in Kathmandu Metropolitan City as partial
requirement of application for permission to construct the building. This Report describes in
brief the Structural Aspects and Design Report of the proposed building. The analysis and
design have been carried out using finite element software ETABS 2017 and foundation has
been designed from SAFE 2016. These softwares provide the Structural Engineer with all the
tools necessary to create, modify, analyze, design, and optimize the structural elements in a
building model. The structure design is intended to be based primarily on the current National
Building Code of Practice of India taking account of relevant British Codes for the provisions
not covered in this and is generally in conformance with NBC of Nepal.

Page | 2
1.2 STRUCTURAL MODELING
A three-dimensional mathematical model of the physical structure should be
used that represents the spatial distribution of the mass and stiffness of the structure to an
extent that is adequate for the calculation of the significant features of its dynamic response.
Thus, the essential requirements of the model is that, it should include the sufficient detail in
geometry, support, material, members, loading, strength, rigidity, stability etc. such that it
reflects the real and true prototype of a physical structure. In modeling, for the vertical loading
system, the deflection on the column in axial direction is so minimal that we can neglect it. It is
because of high rigidity of column in axial direction whereas in horizontal loading system, the
in-plane stiffness of floor is assumed to be very high compared to the stiffness of other frame
members in that plane. It is because of the presence of floor slab. Since, floor slab has very
high in-plane rigidity, the member like column, wall and braces connected to that plane are
assumed to move as a single unit in the lateral direction. This system is known as rigid floor
diaphragm in which beam is monolithically connected with slab providing negligible bending
in the vertical plane.
For the modeling of this building, ETABS 2017 software was used. ETABS 2017 is a
sophisticated, yet easy to use, special purpose analysis and design program developed
specifically for building systems. ETABS 2017 features an intuitive and powerful graphical
interface coupled with unmatched modeling, analytical, design, detailing procedure, powerful
numerical methods and many international design codes all integrated using a common
database. Although quick and easy for simple structures, ETABS 2017 can also handle the
largest and most complex building models, including the wide range of nonlinear behaviors,
making it the tool of choice for structural engineers in the building industry.
For the design of foundation, SAFE 2016 has been used. SAFE is the ultimate tool for
designing concrete floor and foundation systems. From framing layout all the way through to
detail drawing production, SAFE integrates every aspect of the engineering design process in
one easy and intuitive environment. SAFE provides unmatched benefits to the engineer with its
truly unique combination of power, comprehensive capabilities, and ease-of-use.

Page | 3
2.0 STRUCTURAL SYSTEM FOR THE BUILDINGS
The structural system chosen is Moment Resisting RCC Frames and Shear walls at
appropriate locations. Columns and beams have been laid out in plan in coordination with
architectural and services planning that acts jointly support and transmit to the ground those
forces arising from earthquake motions, gravity and live load. Its role becomes increasingly
important with the increase in building height. Thus, the vital criteria for structural systems
are an adequate reserve of strength against failure, adequate lateral stiffness, and an efficient
performance during the service life of the building. The determination of the structural forms
of a building involves the selection and arrangement of the major structural elements to resist
most efficiently the various combinations of gravity and horizontal loadings. The choice of
structural form is strongly influenced by the internal planning, the material and method of
construction, the external architectural treatment, the location and routing of service systems,
the nature and magnitude of the horizontal loading, and the height and proportion of the
building. With regard to horizontal loading, a high-rise building is essentially a vertical
cantilever. As height increases, the lateral force begins to dominate the structural systems and
becomes increasingly important in the overall building system. Strength, rigidity and stability
are the three main factors to consider in the design of all structures. For high-rise building,
rigidity and stability requirement are often the dominant factors in the design. The structural
system of the present building consists of a RC shear-walled framed structure. Shear-walled
frame systems resist the lateral load by a combined action of shear wall and rigid frames. A
shear wall deflects predominantly in a bending mode whereas a rigid frame bends in a shear
mode. As the structural elements are not free to deform independently, a considerable
horizontal interaction develops in the structural systems. The degree of interaction depends
on the relative stiffness of the walls and frames, and the height of the structure. The linear
sway of the moment frame, when combined with the parabolic sway of the shear wall results
in an enhanced stiffness because the wall is restrained by the frame at the upper levels while
at the lower levels the frame is restrained by the wall.

However, the behavior of shear-walled frame is drastically altered if the stiffness of

the walls and the frames are abruptly changed instead of using the same stiffness throughout
the height of the building. Actual behavior of complex shear-walled frame can only be
captured from the numerical analysis.

Page | 4
3.0 GENERAL DATA FOR STRUCTURAL ANALYSIS
Grade of Concrete and Cover to the Reinforcement is provided according to the
provisions of the Indian Code. The appropriate grade of concrete and nominal cover to
reinforcement is governed by the following main considerations:

i) Durability of Concrete including Fire resistance rating

ii) Corrosion Protection of the Reinforcement
iii) Bar Size
iv) Nominal maximum aggregate size

3.1 Grade of Concrete

The Indian Code IS: 456-2000, permits a minimum grade of concrete for reinforced
concrete members as M20 and the following concrete grades shall be used for “normal”
conditions:

Foundation: M25
Column: M40/M30
Beam and slab: M30
Shear Wall: M30

3.2 Reinforcement Steel

All reinforcing steel to be used in the structural elements shall have a yield stress of 500
MPa, (Thermo-Mechanically Treated bars), conforming to IS: 1786-1985.

3.3 Cover to Reinforcements

Clear cover to the main reinforcement in the various structural elements shall be as
follows:

a) Footings (Bottom): 75 mm
Footings (Top and Sides): 75 mm
b) Columns: 40 mm
c) Beams: 25 mm or bar diameter whichever is greater
e) Slabs: 20 mm or bar diameter whichever is greater
f) Stairs (waist slab/folded): 20 mm
g) Shear wall: 25 mm

Page | 5
3.4 Reference Codes
Many international standard codes of practices were adopted for the creation of
mathematical model, its analysis and design. As per the requirements, IS Codes were used for
the load combination in order to check for the worse case during analysis.

Some of the codes used are enlisted below:

A. Loading

Code Description
IS 875: 1987 Part I Dead Loads
IS 875: 1987 Part II Imposed Loads
IS 875: 2015 Part III Wind Loads (Amended in 2016)
IS 875: 1987 Part V Special Loads and Combinations

B. Design of Earthquake Resistance

Code Description
IS 1893:2016 Criteria for earthquake resistant design of structures (Amended in 2017)
Code of practice for earthquake resistant design and construction of
IS 4326:2013
buildings

C. Design of Concrete Elements

Code Description
IS 456:2000 Code of practice for plain and reinforced concrete (Reaffirmed in 2016)
Specification for high strength deformed steel bars and wires for concrete
IS 1786:2008
reinforcement
SP-16 Design aids for reinforced concrete
SP-34 Handbook on concrete reinforcement and detailing

D. Design of Steel Structural Elements

Code Description
IS 800:2007 Use of steel in construction - Code of practice
IS 2062 Steel for general structural purposes

Page | 6
E. Design of Foundations

Code Description
Indian Standard code of practice for design and construction of foundations in soil -
IS 1904
General requirements
IS 2950 Indian Standard code of practice for design and construction of raft foundation (Part - I)
IS 2911 Indian Standard code of practice for design and construction of pile foundations
IS 2974 Code of practice for design and construction of machine foundation

F. Detailing of Structures

Code Description
Ductile Design and Detailing of Reinforced Concrete structures subjected to
IS 13920:2016
lateral forces (Reaffirmed in 2017)

4.0 LOAD CALCULATIONS

4.1 Gravity Loads
Gravity loading is primarily due to the self-weight of the structure, superimposed
dead load and occupancy of the building. Following loads have been considered for the
analysis and design of the building based on the relevant Indian Standards.

4.2 Live Loads

The Live Load for building has been adopted as given IS 875 - Part II.
Live loads used are:
Corridors and Stairs: - 4 kN/m2
File Room: - 5 kN/m2
Kitchen: - 3 kN/m2
Office: - 2.5 kN/m2
Steel Deck: - 2.5 kN/m2
Terrace:- 1.5 kN/m2
Toilet:- 2 kN/m2
Parking= 5 kN/m2
Mechanical Parking= 10 kN/m2

Live load reduction in for calculation of Earthquake load:

For, Live <= 3 kN/m2 - 75% Reduction
Live > 3 kN/m2 - 50% Reduction

Page | 7
4.3 Dead Load
The dead load comprises of self-weight of the structure and loading due to finishes,
floorings, and non-structural walls etc. which are permanent in nature. The self-weight of the
structural elements such as beams, structural walls, columns and slabs is calculated
automatically in the ETABS model by defining the self-weight multiplier as 1. The
superimposed dead load applied either as area loads to slabs or as line loads to beams.

Unit weight of Concrete = 25 kN/m3

Unit weight of floor finish = 24 kN/m3
Unit weight of brick wall = 19.2 kN/m3
Unit weight of Plaster or Mortar = 22 kN/m3
Unit weight of Glass = 27.5 kN/m3

Superimposed Dead Load

Floor Finish = 2 kN/m2 (applied as area loads to slabs.)
Facade Load = 5 kN/m (applied as line loads to beams.)

Page | 8
4.4 Seismic Load
4.4. 1 Seismic Coefficient Method

The Indian Standard IS 1893:2016 contains provisions for both the static analysis and
the dynamic analysis of buildings. Static analysis using equivalent lateral force procedure is
restricted to regular buildings having height less than 15 m in seismic Zone II. At the core of
seismic analysis is the use of response spectra plot as given in figure 2 of IS1893:2016, in
which the spectral acceleration is plotted for wide range of fundamental natural period of the
structures. For the static analysis, the static forces in the structure are derived from the design
seismic base shear (Vb) given by:

Design Seismic Base shear VB = Ah * W

Where,
Ah = Design Horizontal Seismic Coefficient
W = Seismic Weight of the building
Design Horizontal Seismic Coefficient Ah = Z/2 * I/R *Sa/g

Where,
Z = Zone Factor = 0.36 as applicable for structures built in Zone V.
I = Importance factor for the buildings = 1.2.
R = Response Reduction factor = 5.
Sa/g = Average Response Acceleration Coefficient is taken for Soil Type-III
and 5% Damping

As per IS 1893:2016, Clause 7.6.2 the approximate fundamental natural period of vibration in
seconds of the building which is moment resisting frame is given by empirical expression
Ta = 0.075h0.75

Time Period Calculation:

Height of the Building Taken = 36.4 m

Ta= 0.075x(36.4) 0.75= 1.114 Sec

Page | 9
4.4.2 Dynamic Analysis:

Response Spectrum method was chosen for the dynamic analysis as per IS 1893:2016,
Clause no. 7.7. The no. of mode shapes is taken to ensure that the sum total of modal masses of
all modes considered is at least 90% of the total seismic mass. The peak response quantities
have been combined as per CQC (Complete Quadratic Combination) in accordance with IS:
1893-2016 has been followed for modal combinations.

The scale factors used are as:

Scale Factor in X direction Scale Factor in Y direction

1.019 1.141

Comparison of Base shears from Static analysis and Dynamic analysis after scaling:
Base Shear from Static Base Shear from Dynamic
Analysis(kN) Analysis(kN)
X direction Y direction X direction Y direction
3466.44 3466.44 3466.1021 3466.2819

Page | 10
4.5 Soft Storey
A soft storey can be detected by comparing the stiffness of adjacent storeys.
Soft storeys are present in buildings with open fronts on the ground floor or tall storeys.

Fig 2: Open Ground Storey and Bare Frame

There is no soft storey in the proposed building since no storey level has change
in mass and stiffness in considerate amount.

Page | 11
5.0 LOAD COMBINATIONS

The load combination has been taken as per IS 1893:2016. The load combinations
used in ETABS analysis are listed below.

S.No. For Concrete Design

1 1.5DL+1.5LL
2 1.2DL+1.2LL±1.2EQX
3 1.2DL+1.2LL±1.2EQY
4 1.5DL±1.5EQX
5 1.5DL±1.5EQY
6 0.9DL±1.5EQX
7 0.9DL±1.5EQY
8 1.2DL+1.2LL±1.2(EQX±0.3EQY±0.3EQZ)
9 1.2DL+1.2LL±1.2(EQY±0.3EQX±0.3EQZ)
10 1.5DL±1.5(EQX±0.3EQY±0.3EQZ)
11 1.5DL±1.5(EQY±0.3EQX±0.3EQZ)
12 0.9DL±1.5(EQX±0.3EQY±0.3EQZ)
13 0.9DL±1.5(EQY±0.3EQX±0.3EQZ)

Page | 12
6.0 ANALYSIS AND DESIGN PROCEDURE

Space frame analysis using ETABS 2017 software has been undertaken to obtain
refined results for all load combinations in accordance with Indian Standard Code.
The RCC design shall be based on IS: 456-2000 Code of practice for plain and
reinforced concrete, following Limit state philosophy. Structural design for typical members
has been done for the combination of loads that produces maximum stress in the structural
elements, and in turn requires maximum reinforcing steel provisions.
The design of Columns and Beams is done directly using ETABS 2017 design
software. The design of Slab is done by in house developed Worksheets in Excel. The size of
columns and beams are provided as per requirement. Footing design is directly done using
SAFE 2016.

General Information on Structural Elements of the Building

Grade of
Element Description Concrete Remarks
500 mm X 500 mm M40
Column 750 mm X 750 mm M40
750 mm X 750 mm M30
600 mm X 350mm M30 Main Beam
Beam 250 mm X 600 mm M30 Main Beam
500 mm X 300 mm M30 Secondary Beam
160 mm M30
Slab 150 mm M30
200 mm M30
350 mm M30 Basement Wall
Shear Wall 350 mm M30 Lift Wall
Foundation D = 1200mm M25 Raft+Pile Foundation

Page | 13
7.0 MODELING IN ETABS 2017

Fig 3: 3D Model of Tower Block in ETABS 2017

Page | 14
Fig 6: Floor Finish at 4th Floor

Page | 15
Fig 9: Live Load(>3kN/m2) at 4th Floor

Page | 16
Fig 10: Live Load (<3kN/m2) at 4th Floor.

Page | 17
Fig 13: Brick Wall Load at Elevation C

Page | 18
8.0 DEFLECTION AND STOREY DRIFT

In order to control deflection of structural elements, the criteria given in the Clause
23.2 of IS 456:2000 is proposed to be used.
To control overall deformation due to earthquake load, the criteria given in clause
7.11 of IS1893:2016 is applied. The maximum deflection in any story due to the minimum
specified design lateral force, with partial load factor of 1.0 shall not exceed 0.004 times the
story height. Furthermore, the drift shall not exceed 0.004 in any case.

Building height = 36.5 m

Permissible deflection = 0.4% of 36.5mm = 146 mm
The maximum deflection in the model is 49.17 mm which is within permissible limit.
The following table shows the maximum and average displacements in the model:

TABLE: Story Max/Avg Displacements

Load
Story Case/Combo Direction Maximum Average Ratio
mm mm
G+10 EQy 3 Y 49.177 45.429 1.083
G+10 EQy 1 Y 45.839 44.326 1.034
G+9 EQy 3 Y 44.864 41.829 1.073
G+10 EQy 2 Y 43.945 43.223 1.017
G+9 EQy 1 Y 42.195 40.958 1.03
G+9 EQy 2 Y 40.647 40.087 1.014
G+8 EQy 3 Y 40.161 36.518 1.1
G+8 EQy 1 Y 38.067 36.607 1.04
G+8 EQy 2 Y 37.417 36.696 1.02
G+10 EQx 2 X 37.195 31.101 1.196
G+9 EQx 2 X 35.641 28.303 1.259
G+7 EQy 3 Y 35.285 32.305 1.092
G+10 EQx 1 X 33.759 30.74 1.098
G+7 EQy 1 Y 33.539 32.377 1.036
G+7 EQy 2 Y 33.102 32.448 1.02
G+9 EQx 1 X 31.102 27.113 1.147
G+8 EQx 2 X 30.853 22.103 1.396
G+10 EQx 3 X 30.436 30.38 1.002
G+6 EQy 3 Y 29.948 27.6 1.085
G+6 EQy 1 Y 28.54 27.655 1.032
G+6 EQy 2 Y 28.289 27.711 1.021
G+8 EQx 1 X 26.894 21.547 1.248
G+9 EQx 3 X 26.563 25.923 1.025
G+7 EQx 2 X 25.74 18.416 1.398
Page | 19
G+5 EQy 3 Y 24.373 22.513 1.083
G+5 EQy 1 Y 23.248 22.554 1.031
G+5 EQy 2 Y 23.069 22.595 1.021
G+8 EQx 3 X 22.935 20.99 1.093
G+7 EQx 1 X 22.392 17.925 1.249
G+6 EQx 2 X 20.647 14.787 1.396
G+7 EQx 3 X 19.044 17.434 1.092
G+4 EQy 3 Y 18.592 17.192 1.081
G+6 EQx 1 X 17.933 14.384 1.247
G+4 EQy 1 Y 17.738 17.222 1.03
G+4 EQy 2 Y 17.618 17.251 1.021
G+5 EQx 2 X 16.394 11.826 1.386
G+6 EQx 3 X 15.218 13.98 1.089
G+5 EQx 1 X 14.236 11.514 1.236
G+3 EQy 3 Y 12.854 11.892 1.081
G+4 EQx 2 X 12.361 8.998 1.374
G+3 EQy 1 Y 12.259 11.912 1.029
G+3 EQy 2 Y 12.2 11.933 1.022
G+5 EQx 3 X 12.077 11.201 1.078
G+4 EQx 1 X 10.735 8.772 1.224
G+4 EQx 3 X 9.109 8.545 1.066
G+3 EQx 2 X 8.574 6.312 1.359
G+2 EQy 3 Y 7.498 6.946 1.079
G+3 EQx 1 X 7.451 6.163 1.209
G+2 EQy 2 Y 7.162 6.973 1.027
G+2 EQy 1 Y 7.141 6.96 1.026
G+3 EQx 3 X 6.327 6.014 1.052
G+2 EQx 2 X 5.155 3.856 1.337
G+2 EQx 1 X 4.485 3.774 1.188
G+2 EQx 3 X 3.815 3.692 1.033
G+1 EQy 3 Y 3.022 2.855 1.058
G+1 EQy 2 Y 3.021 2.874 1.051
G+1 EQy 1 Y 2.874 2.865 1.003
G+1 EQx 2 X 2.227 1.717 1.297
G+1 EQx 1 X 1.947 1.687 1.154
G+1 EQx 3 X 1.668 1.657 1.007
PLINTH EQy 2 Y 0.488 0.409 1.194
PLINTH EQy 1 Y 0.472 0.403 1.172
PLINTH EQy 3 Y 0.457 0.397 1.149
PLINTH EQx 2 X 0.22 0.2 1.105
PLINTH EQx 3 X 0.215 0.201 1.069
PLINTH EQx 1 X 0.204 0.2 1.017

Page | 20
GF EQy 2 Y 0.148 0.136 1.087
GF EQy 1 Y 0.146 0.133 1.102
GF EQy 3 Y 0.145 0.13 1.116
GF EQx 3 X 0.116 0.104 1.114
GF EQx 1 X 0.108 0.099 1.086
GF EQx 2 X 0.1 0.094 1.056
GF EQy 2 X 0.081 0.062 1.304
GF EQy 1 X 0.079 0.058 1.368
GF EQy 3 X 0.078 0.054 1.441
G-1 EQx 3 X 0.046 0.041 1.122
G-1 EQx 1 X 0.043 0.041 1.049
G-1 EQx 2 X 0.041 0.04 1.025
G-1 EQy 3 Y 0.04 0.036 1.11
G-1 EQy 1 Y 0.038 0.036 1.05
G-1 EQy 2 Y 0.037 0.037 1.009
GF EQx 3 Y 0.021 0.014 1.55
G-1 EQy 3 X 0.008 0.004 2.131
G-1 EQy 1 X 0.006 0.004 1.456
G-1 EQy 2 X 0.005 0.005 1.076

Similarly, maximum drift in the model is 0.00158 which is less than 0.004, i.e. within
the permissible limit.

TABLE: Story Drifts

Load
Story Case/Combo Direction Drift Label X Y Z
m m m
G+5 EQy 3 Y 0.00158 22 0 9.43 25.3
G+4 EQy 3 Y 0.00157 22 0 9.43 21.65
G+6 EQy 3 Y 0.00153 22 0 9.43 28.95
G+5 EQy 1 Y 0.00151 22 0 9.43 25.3
G+9 EQx 3 X 0.00151 40 12.291 4.43 39.9
G+4 EQy 1 Y 0.0015 22 0 9.43 21.65
G+5 EQy 2 Y 0.00149 42 18.936 0 25.3
G+4 EQy 2 Y 0.00148 42 18.936 0 21.65
G+3 EQy 3 Y 0.00147 22 0 9.43 18
G+7 EQy 3 Y 0.00146 22 0 9.43 32.6
G+6 EQy 1 Y 0.00145 22 0 9.43 28.95
G+6 EQy 2 Y 0.00143 42 18.936 0 28.95
G+10 EQx 3 X 0.00141 40 12.291 4.43 43.55
G+3 EQy 1 Y 0.0014 22 0 9.43 18
G+8 EQx 2 X 0.0014 19 1.871 23.264 36.25
G+7 EQx 2 X 0.0014 19 1.871 23.264 32.6

Page | 21
G+3 EQy 2 Y 0.00138 33 18.936 19.32 18
G+7 EQy 1 Y 0.00137 22 0 9.43 32.6
G+9 EQx 1 X 0.00134 40 12.291 4.43 39.9
G+8 EQy 3 Y 0.00134 22 0 9.43 36.25
G+7 EQy 2 Y 0.00132 99 18.936 15.82 32.6
G+9 EQx 2 X 0.00131 19 1.871 23.264 39.9
G+9 EQy 3 Y 0.00129 21 0 14.23 39.9
G+10 EQx 2 X 0.00128 29 12.291 19.32 43.55
G+10 EQx 1 X 0.00126 40 12.291 4.43 43.55
G+8 EQy 1 Y 0.00124 22 0 9.43 36.25
G+8 EQx 1 X 0.00123 19 1.871 23.264 36.25
G+2 EQy 3 Y 0.00123 22 0 9.43 14.35
G+7 EQx 1 X 0.00122 19 1.871 23.264 32.6
G+10 EQy 3 Y 0.00118 21 0 14.23 43.55
G+8 EQy 2 Y 0.00118 42 18.936 0 36.25
G+2 EQy 1 Y 0.00117 22 0 9.43 14.35
G+6 EQx 2 X 0.00117 19 1.871 23.264 28.95
G+2 EQy 2 Y 0.00113 42 18.936 0 14.35
G+9 EQy 1 Y 0.00113 21 0 14.23 39.9
G+5 EQx 2 X 0.00111 19 1.871 23.264 25.3
G+8 EQx 3 X 0.00107 19 1.871 23.264 36.25
G+7 EQx 3 X 0.00105 19 1.871 23.264 32.6
G+4 EQx 2 X 0.00104 19 1.871 23.264 21.65
G+9 EQy 2 Y 0.00103 23 12.291 10.92 39.9
G+6 EQx 1 X 0.00101 19 1.871 23.264 28.95
G+10 EQy 1 Y 0.001 21 0 14.23 43.55
G+5 EQx 1 X 0.00096 19 1.871 23.264 25.3
G+3 EQx 2 X 0.00094 19 1.871 23.264 18
G+10 EQy 2 Y 0.00091 29 12.291 19.32 43.55
G+4 EQx 1 X 0.0009 19 1.871 23.264 21.65
G+6 EQx 3 X 0.00086 19 1.871 23.264 28.95
G+5 EQx 3 X 0.00081 19 1.871 23.264 25.3
G+3 EQx 1 X 0.00081 19 1.871 23.264 18
G+2 EQx 2 X 0.0008 19 1.871 23.264 14.35
G+4 EQx 3 X 0.00076 19 1.871 23.264 21.65
G+1 EQy 3 Y 0.00074 22 0 9.43 10.7
G+1 EQy 1 Y 0.0007 22 0 9.43 10.7
G+2 EQx 1 X 0.0007 19 1.871 23.264 14.35
G+1 EQy 2 Y 0.00069 33 18.936 19.32 10.7
G+3 EQx 3 X 0.00069 19 1.871 23.264 18
G+2 EQx 3 X 0.00059 19 1.871 23.264 14.35
G+1 EQx 2 X 0.00055 19 1.871 23.264 10.7

Page | 22
G+1 EQx 1 X 0.00048 19 1.871 23.264 10.7
G+1 EQx 3 X 0.00041 19 1.871 23.264 10.7
PLINTH EQy 2 Y 0.00034 42 18.936 0 7.05
PLINTH EQy 1 Y 0.00033 42 18.936 0 7.05
PLINTH EQy 3 Y 0.00032 42 18.936 0 7.05
PLINTH EQx 2 X 0.00015 15 18.936 21.734 7.05
PLINTH EQx 1 X 0.00013 15 18.936 21.734 7.05
PLINTH EQy 2 X 0.00013 33 18.936 19.32 7.05
PLINTH EQx 3 X 0.00012 15 18.936 21.734 7.05
PLINTH EQy 1 X 0.00012 33 18.936 19.32 7.05
PLINTH EQy 3 X 0.00011 33 18.936 19.32 7.05
GF EQy 2 Y 5.7E-05 16 12.291 21.734 6
GF EQy 1 Y 5.6E-05 16 12.291 21.734 6
GF EQy 3 Y 5.5E-05 16 12.291 21.734 6
GF EQx 2 X 4.1E-05 16 12.291 21.734 6
GF EQx 1 X 3.8E-05 16 12.291 21.734 6
GF EQx 3 X 3.5E-05 16 12.291 21.734 6
G-1 EQx 2 X 2.4E-05 60 -0.513 23.264 2.9
GF EQy 3 X 2.3E-05 33 18.936 19.32 6
G-1 EQx 1 X 2.2E-05 60 -0.513 23.264 2.9
G-1 EQx 3 X 0.00002 60 -0.513 23.264 2.9
G-1 EQy 1 Y 1.8E-05 60 -0.513 23.264 2.9
G-1 EQy 3 Y 1.8E-05 60 -0.513 23.264 2.9
G-1 EQy 2 Y 1.7E-05 60 -0.513 23.264 2.9
GF EQx 3 Y 6E-06 13 21.361 21.734 6
GF EQx 1 Y 5E-06 13 21.361 21.734 6

Page | 23
9.0 MODAL PARTICIPATING MASS RATIOS

TABLE: Modal Participating Mass Ratios

Case Mode Period UX UY Sum UX Sum UY RZ Remarks
sec
Modal 1 1.005 0.0012 0.7177 0.0012 0.7177 0.0017 Translation in X Direction
Modal 2 0.758 0.5858 0.0003 0.587 0.718 0.0983 Translation in Y Direction
Modal 3 0.515 0.0956 0.0026 0.6826 0.7206 0.6086 Rotation/Torsional
Modal 4 0.319 0.0256 0.0921 0.7082 0.8127 0.0044
Modal 5 0.306 0.1055 0.0298 0.8137 0.8424 0.0017
Modal 6 0.213 0.0273 0.0077 0.841 0.8502 0.0981
Modal 7 0.171 0.0686 3.255E-05 0.9096 0.8502 0.0409
Modal 8 0.157 0.0009 0.0494 0.9106 0.8996 0.0138
Modal 9 0.127 4.512E-05 0.0117 0.9106 0.9113 0.0405
Modal 10 0.112 0.0418 0 0.9524 0.9113 0.0011
Modal 11 0.094 0.0013 0.0135 0.9537 0.9249 0.0241
Modal 12 0.084 0.0037 0.0174 0.9575 0.9423 0.0149
We have,
90% mode participation in exactly 9 modes
Corresponding Time period (T) = 0.127 secs
Corresponding frequency (f) = 1/T = 7.87 Hz
As per IS 1893:2016 Clause 7.7.5.2, f<33 Hz, which is OK.

Page | 24
10.0 DESIGN OF STRUCTURAL ELEMENTS
10.1 Design of Column

Sample Design of Column

General Information of Column to be designed:

Column: C14
Story: Ground
ETABS Concrete Frame Design
IS 456:2000 Column Section Design

Column Element Details Type: Ductile Frame (Summary) (Part 1 of 2)

Unique
Level Element Section ID Combo ID Station Loc
Name
1.3 COL 750x 750 - R24. 1.2DL + 1.2LL -
G+1 C14 143 3050
M40 1.2(EQY-0.3EQX)

Column Element Details Type: Ductile Frame (Summary) (Part 2 of 2)

Length
LLRF
(mm)
3650 1

Section Properties
Cover (Torsion)
b (mm) h (mm) dc (mm)
(mm)
750 750 67.1 30

Page | 25
 Material Properties
Lt.Wt Factor
Ec (MPa) fck (MPa) fy (MPa) fys (MPa)
(Unitless)
31622.78 40 1 500 415

Design Code Parameters

ɣC ɣS
1.5 1.15

Axial Force and Biaxial Moment Design For Pu , Mu2 , Mu3

Rebar
Design Pu Design Mu2 Design Mu3 Minimum M2 Minimum M3 Rebar %
Area
kN kN-m kN-m kN-m kN-m %
mm²
2207.6415 25.2746 199.4299 68.6577 68.6577 4500 0.8

Axial Force and Biaxial Moment Factors

Initial Additional Minimum
K Factor Length
Moment Moment Moment
Unitless mm
kN-m kN-m kN-m
Major
0.952085 3050 30.4865 0 68.6577
Bend(M3)
Minor
0.926186 3050 102.8509 0 68.6577
Bend(M2)

Shear Design for Vu2 , Vu3

Shear Vu Shear Vc Shear Vs Shear Vp Rebar Asv /s
kN kN kN kN mm²/m
Major, Vu2 109.2767 367.5521 204.8556 109.2767 831.33
Minor, Vu3 166.4229 367.5521 204.8556 166.4229 831.33

Joint Shear Check/Design

Joint Shear Shear Shear Shear Joint Shear
Force VTop Vu,Tot Vc Area Ratio
kN kN kN kN cm² Unitless
Major Shear, 439.413
0 78.0548 3438.977 5437.5 0.128
Vu2 7
Minor Shear, 118.873 670.895 3557.562
0 5625 0.189
Vu3 5 1 4

Page | 26
 (1.4) Beam/Column Capacity Ratio
Major Minor
Ratio Ratio
0.18 0.275

Additional Moment Reduction Factor k (IS 39.7.1.1)

Ag Asc Puz Pb Pu k
cm² cm² kN kN kN Unitless
11812.499 4647.838 2207.641
5625 45 1
9 8 5

Additional Moment (IS 39.7.1)

Section KL/Dept KL/Dept Ma
Consider Length KL/Depth
Depth h h Moment (kN-
Ma Factor Exceeded
(mm) Ratio Limit m)
Major Bending
Yes 0.836 750 3.872 12 No 0
(M3 )
Minor Bending
Yes 0.836 750 3.766 12 No 0
(M2 )

For main bars:

• Ast(required) = 4500 mm2

• Provide 24-20mm φ bars

• Ast (provided) = 7539.84 mm2

• Here, Ast(provided) > Ast(required) OK

For lateral ties (IS 456:2000) Clause 26.5.3.2(c):

• Spacing shall be less than the least of:

i. Least lateral dimension = 750 mm

ii. 16 φ = 16 x 20 = 320 mm

iii. 300 mm

• Provide lateral ties 8φ @100mm c/c at edges and 8φ @150mm c/c at mid-span.

All the columns are designed in a similar way.

Please refer structural drawings for further details.

Page | 27
 10.2 Design of Beam

Sample Design of Beam

General Information of Beam to be designed:

Story: G+1
Beam: B65
ETABS Concrete Frame Design
IS 456:2000 Beam Section Design

Beam Element Details Type: Ductile Frame (Summary)

Elemen Unique Station Length
Level Section ID Combo ID LLRF
t Name Loc (mm)
2.1 B2 39. 1.5DL - 1.5 (EQY-
G+1 B65 304 0 3310 1
(600x500) 0.3EX-0.3EQZ)

Section Properties
b (mm) h (mm) bf (mm) ds (mm) dct (mm) dcb (mm)
500 600 500 0 30 30

Material Properties
Lt.Wt Factor
Ec (MPa) fck (MPa) fy (MPa) fys (MPa)
(Unitless)
27386.13 30 1 500 415

Design Code Parameters

ɣC ɣS
1.5 1.15

Page | 28
 Factored Forces and Moments
Factored Factored Factored Factored
Mu3 Tu Vu2 Pu
kN-m kN-m kN kN
-339.1854 1.4967 291.8635 0

Design Moments, Mu3 & Mt

Factored Factored Positive Negative
Moment Mt Moment Moment
kN-m kN-m kN-m kN-m
-339.1854 1.9369 0 -341.1223

Design Moment and Flexural Reinforcement for Moment, Mu3 & Tu

Design Design -Moment +Moment Minimum Required
-Moment +Moment Rebar Rebar Rebar Rebar
kN-m kN-m mm² mm² mm² mm²
Top (+2
-341.1223 1512 0 1512 485
Axis)
Bottom (-2
0 756 0 0 756
Axis)

Shear Force and Reinforcement for Shear, Vu2 & Tu

Shear Ve Shear Vc Shear Vs Shear Vp Rebar Asv /s
kN kN kN kN mm²/m
379.0184 0 383.8078 254.0117 1865.9

Torsion Force and Torsion Reinforcement for Torsion, Tu & VU2

Tu Vu Core b1 Core d1 Rebar Asvt /s
kN-m kN mm mm mm²/m
291.863
1.4967 460 560 734.18
5

Page | 29
From the obtained data, the rebars for the beam are calculated as follows:

Left 1522 mm2

Top Reinf. Bar Area Middle 485 mm2
Right 951 mm2
Ast (required)
Left 941 mm2
Bottom Reinf. Bar Area Middle 749 mm2
Right 749 mm2
Provide Top Bars: 4-25φ (TH.) + 2-25 φ (EX.)
Bottom Bars: 4-25φ (TH.) + 2-20 φ (EX.)
Left 2945 mm2
Top Reinf. Bar Area Middle 1963.50 mm2
Right 2945 mm2
Ast(provided)
Left 2591.82 mm2
Bottom Reinf. Bar Area Middle 1963.50 mm2
Right 2591.82 mm2

All the beams are designed in a similar way.

Please refer structural drawings for further details.

Page | 30
10.3 Design of Footing

A. Input Data
a. Soil Subgrade Modulus
Soil Bearing Capacity = 150 kN/m2
Soil Spring Modulus = 7500 kN/m3

b. Mat Thickness
Mat thickness of 1200 mm is provided.

c. Pile Spring Constant(Ks)

Ks= Pile Capacity/ Allowable Deflection

B. Analysis

a. Soil Pressure

Fig 7: Soil Pressure Diagram for DL+LL combination

Soil Pressure (123.79 kN/m2) is less than allowable soil bearing capacity (150 kN/m2).

b. Punching Shear Check

Page | 31
 Fig 8: Punching Shear Capacity Ratios

Since all punching shear Capacity Ratios are less than 1, the foundation is safe against
Punching Shear.

Page | 32
C. Design
Design of foundation is directly done using the software. The approach chosen is Strip
Based Method. The reinforcement is provided as per the demand.

Fig 12: Top and Bottom Reinforcement Intensity in X

Fig 12: Top and Bottom Reinforcement Intensity in Y

Page | 33
10.4 Design of Slab

Sample Design of Slab

General Information of Slab to be designed:
Slab: F19
Story: G+6
1.General information:
Concrete Grade= M 30
Steel Grade= Fe 500

As per IS 456:2000,
Case No.= 4
Two Adjacent Edges
Type of panel= Discontinuous

2.Thickness of slab and durability consideration:

Short Span, lx = 4035.5 mm
Long Span,ly = 4430 mm
Approx L/d permissible= 32
Approx d= 126.11 mm
Adopting, overall depth(D)= 150 mm
Assuming, clear cover= 20 mm
and diameter of bar= 8 mm
Effective depth of slab(d)= 126 mm

Effective short span (Lx)= 4161.5 mm

Effective long span (Ly)= 4556 mm
Ly/Lx= 1.09
Hence, it is a two way slab.

3.Calculation of Design Load:

Self weight = 3.75 kN/m2
Finishing &Partition= 2 kN/m2
Live Load = 4 kN/m2
Total Load = 9.75 kN/m2
Factored load = 14.63 kN/m2
Considering unit width of Slab,
w= 14.63 kN/m

Page | 34
4.Moment and Reinforcement Calculation:
Moment
Coefficient(α)
Moments considered (kN.m)
Support (-ve) 0.053 12.677
Shorter Span
mid span(+ve ) 0.040 10.123
Support (-ve) 0.047 11.198
Longer Span
mid span(+ve ) 0.035 8.339

Hence,
the moment to be considered (Mu)= 12.677 kN.m
Solving, Mu=0.87*fy*Ast*d*(1-Ast*fy/bd.fck)
2
Ast= 238.8 mm /m
Also, Minimum
mm2/m
Ast(0.25%)= 315
2
Hence, Limiting Ast= 315 mm /m
dia bars
c/c
Providing 10 @ 140
2
Ast provided= 628 mm /m
Provided Ast is sufficient

5. Check for Deflection:

shorter span of critical slab= 4161.5 mm
spacing of bars= 140 mm
overall depth of slab= 150 mm
eff depth of slab= 126 mm
% Tension reinforcement= 0.499%
fs= 146
From graph Fig 4 IS 456-2000,
Modification factor = 2
Basic L/d= 20.000
Permissible L/d ratio= 40
Provided L/d ratio= 33.03

Hence,
Provide 10 mmφ bars @ 140 mm c/c in X-direction
Provide 10 mmφ bars @ 140 mm c/c in Y-direction.

Page | 35
 10.4 Design of Shear wall

Sample Design of Shear wall:

Shear Wall: SW2

Story: Ground Floor

ETABS Shear Wall Design

IS 456:2000 Pier Design

Pier Details
Centroid X Centroid Y Length Thickness
Story ID Pier ID LLRF
(mm) (mm) (mm) (mm)
PLINTH P6 12291 900 1800 350 1

Material Properties
Lt.Wt Factor
Ec (MPa) fck (MPa) fy (MPa) fys (MPa)
(Unitless)
27386.13 30 1 500 415

Design Code Parameters

MinEcc MinEcc
ΓS ΓC IPMAX IPMIN PMAX
Major Minor
1.15 1.5 0.04 0.0025 0.8 Yes Yes

Pier Leg Location, Length and Thickness

Station Left X1 Left Y1 Right X2 Right Y2 Length Thickness
ID
Location mm mm mm mm mm mm
Top Leg 1 12291 0 12291 1800 1800 350
Bottom Leg 1 12291 0 12291 1800 1800 350

Flexural Design for Pu, Mu2 and Mu3

Required Required Current
Station Flexural Pu Mu2 Mu3 Pier Ag
Rebar Area Reinf Reinf
Location Combo kN kN-m kN-m mm²
(mm²) Ratio Ratio
759.167 - -
Top 8304 0.0132 0.0029 DWal14 630000
4 42.9384 2654.7212
-
Bottom 5859 0.0093 0.0029 DWal14 24.476 1715.909 630000
38.6439

Page | 36
 Shear Design
Station Rebar Pu Mu Vu Vc Vc + Vs
ID Shear Combo
Location mm²/m kN kN-m kN kN kN
3486.084 - 421.293
Top Leg 1 875 DWal8 74.3395 875.989
5 705.8108 4
1715.90 1020.897
Bottom Leg 1 1497.3 DWal14 -38.6439 242.822 1020.8976
9 6

Vertical Bars:
• Ast(required) = 8304 mm2
• Provide 20 φ bars in 32 no.s
• Ast (provided) =10053.12 mm2
• Here, Ast(provided) > Ast(required)

Horizontal Bars:

12mm φ bars @100mm c/c

All the shear walls are designed in a similar way.

Please refer structural drawings for further details.

Page | 37